Photonitrosation of normal paraffins

ABSTRACT

A process for producing normal paraffin oximes and, in particular, normal paraffin oximes having from 10 to 13 carbon atoms wherein a C10 to C13 normal paraffin is photochemically reacted with a gaseous nitrosating agent where the photolytic reaction is conducted under the influence of a sodium arc lamp producing light in the wavelength of about 380 millimicrons to about 760 millimicrons and preferably where the principal emission spectra is from about 550 to 650 millimicrons.

United States Patent 1 Rigdon et a].

[ 1 Feb. 20, 1973 [54] PHOTONITROSATION OF NORMAL PARAFFINS [75]Inventors: Orville W. Rigdon, Groves; Robert S. Edwards; Edward H.Holst, both of Nederland, all of Tex.

[73] Assignee: Texaco Inc., New York, NY. 22 Filed: March 15, 1971 [21]Appl. No.: 124,473

Related U.S. Application Data [63] Continuation-impart of Ser. No.674,612, Oct. 11,

[52] US. Cl ..204/162 XN [51] Int. Cl. ..B0lj 1/10 [58] Field of Search..204/ 162 XN; 260/566 A [56] References Cited UNITED STATES PATENTSRigdon et a1 ..204/162 XN R25,937 12/1965 Ito ..204/162 XN 3,048,6348/1962 Mueller et a1 ...204/162 XN 3,129,155 4/1964 Ito et a1 ..204/162XN Primary ExaminerBenjamin R. Padgett Attorney-Thomas l-l. Whaley andCarl G. Ries [57] ABSTRACT 10 Claims, No Drawings 1 PHOTONITROSATION OFNORMAL PARAFFINS CROSS REFERENCE TO RELATED APPLICATION BACKGROUND OFTHE INVENTION This invention relates to a process for producing oximes.In particular this invention relates to the manufacture of highmolecular weight oximes by photochemically reacting a higher molecularweight normal paraffin and a nitrosation agent.

The preparation of low molecular weight cycloaliphatic oximes byphotonitrosating cycloalkanes is known and disclosed in U.S. Pat. Nos.3,129,155; 3,309,298, and RE 25,937. Substituting higher molecularweight normal paraffins, that is, normal paraffins having from to 13carbon atoms in the above known procedures, resulted substantially inthe formation of ketones or amides. Continued investigation into theapplicability of these procedures when photonitrosating higher molecularweight normal paraffins confirmed that at best only low yields and lowselectivity to the corresponding oximes resulted. Moreover, from acommercial sense these processes were not only economically unattractivebut impractical.

It is therefore an object of this invention to provide an efficientprocess for the preparation of oximes from normal paraffins.

Another object of this invention is to provide a process for thepreparation of oximes from normal paraffins in high yields.

Yet another object of this invention is to provide a process having highselectivity for the preparation of oximes from normal paraffins.

A further object of this invention is to provide a photolytic processemploying efficient light sources.

Other objects and advantages will become apparent from a reading of thefollowing detailed description and examples.

SUMMARY OF THE INVENTION Broadly, this invention contemplates a processfor the manufacture of normal paraffin oximes which comprises:

a. photochemically reacting a normal paraffin having from 10 to 13carbon atoms with a gaseous nitrosating agent selected from the groupconsisting of nitrosyl halides, nitrosyl sulfuric acid, nitrogen oxideand chlorine, nitrogen peroxide and chlorine each alone and in admixturewith hydrogen chloride, where said nitrosating agent partial pressureranges from about 125 to 625 MM Hg under the influence of a sodium arclamp providing essentially all light emission at a wavelength from about380 millimicrons and up to about 760 millimicrons,

b. separating unreacted normal paraffin and the reaction products of(a),

c. neutralizing said separated reaction products of (b), and

d. separating and recovering normal paraffin oximes.

The paraffin hydrocarbons contemplated in this invention are straightchain aliphatic hydrocarbons containing at least 10 carbon atoms andparticularly nparaffms having from 10 to 13 carbon atoms. Suchhydrocarbons include n-decane, n-undecane, ndodecane, n-tridecane, andmixtures thereof. Typical paraffm hydrocarbon mixtures applicable tothis invention include hydrocarbon mixtures comprising 10 to 13 carbonatoms which are obtained from middle distillates by adsorption inmolecular sieves.

Applicable nitrosation agents or components of nitrosating mixturesinclude, nitrosyl halides, nitrosyl sulfuric acid, hydrogen halides,halogens, nitrogen oxide, nitrogen peroxide, etc. Mixed nitrosatingagents such as nitric oxide and chlorine are similarly contemplated inmolar ratios, for example, ranging from 3:1 to about 1:1. Thenitrosating agent may be diluted with hydrogen chloride, nitrogen, orother gases'inert to the photolytic reaction. Mixtures of inert gases isalso contemplated.

An important aspect of this invention relates to the concentration ofnitrosating agent dissolved in the normal paraffin during the course ofthe reaction. The concentration, best expressed in terms ofphotonitrosating agent partial pressure, must be controlled withinnarrow limits so as to provide high oxime yield. It has been found thatwhen the photochemical reaction is carried out under a partial pressureof nitrosating agent ranging from about to 625 and preferably between200 and 400 mm Hg, high molar yields of oxime up to 92 percent andhigher can be realized. Partial pressures below 125 mm Hg and above 625mm Hg significantly reduced oxime formation.

In another embodiment related to the high conversion of normal paraffinto the corresponding oxime, the reaction is permitted to proceed underthe influence of light of selected wavelengths influencing both oximeselectivity and yield. Investigations have shown that exclusion ofwavelengths shorter than 200 millimicrons and preferably excludingwavelengths below 280 millimicrons materially alter the process andproduct formed thereby. Experiments conducted employing normal paraffinswithin the ranges stated above and nitrosyl chloride as reactants underthe influence of unfiltered and filtered light, resulted in an oximeselectivity of only from 10 to 40 percent with unfiltered lightincluding wavelengths shorter than 200 millimicrons, the remainder beingprimarily ketones. Where filtered light was employed selectivity to thecorresponding oxime was 93.5 percent. Moreover, filtered light not onlymaterially affected selectivity but additionally and significantlyaffected yield. In the same experiment it was observed that oximeformation rate was approximately 50 percent greater under the influenceof light excluding the shorter wavelengths than under the influence oflight permitting all wavelengths emitted from a mercury arc lamp toinfluence the reaction.

Filtered light may be provided to the reaction zone in a number of ways.For example various glasses capable of inhibiting the passage ofundesired wavelengths may be employed, that is, the reaction walls mayconsist of such materials or a glass filter may be interposed betweenthe light source and the reaction zone. Among the filtering glasseswhich may be employed we mention Pyrex 7740, Coming glass Nos. 0160,7380, 3850 and Corex 9700 and in general those glasses inhibitingultraviolet light transmission of wavelengths of below 200 millimicronsand preferably below 280 millimicrons.

In a highly preferred embodiment, we employ a sodium arc lamp whereessentially all light emission is at a wavelength of from about 380millimicrons to about 760 millimicrons. The use of the visible radiationis desirable for photonitrosation in view of the higher quantum count,that is photons per watt, which in turn provides increased oximeproduction. In addition to minimizing byproduct formation duringphotonitrosation of n-parafflns, the sodium arc lamp permits greaterphotonitrosation efficiency by converting more of the electrical powerconsumed to light having a wavelength of from about 380 to 760millimicrons. Preferably at least 50 percent of the emission of the lamphas wavelengths of from about 550 to 650 millimicrons. In contrast tothe mercury arc lamps where short wavelength radiation is filtered outresulting in a substantial loss in efficiency, the sodium arc lampscontemplated herein require no filtering devices and employ to fulladvantage the total radiated power. Further, more than twice as muchinput power is converted to usable light in the range of 380760millimicron in sodium arc lamps as compared to mercury arc lamps. Whilesodium arc lamps in general may be employed including those producingnearly monochromatic radiation in the range of 578 to 600 millimicrons,we prefer to employ those having an emission spectrum considerablybroader where at least 50 percent of the lamp emission is in thewavelengths of from about 550 to 650 millimicrons.

An additional embodiment further influencing yield and selectivityrelates to the use of a polybasic acid such as sulfuric or phosphoricacid, flowing along the surface of the reaction vessel. Sulfuric acidhas previously been suggested as a means for carrying out continuousreactions without the occurrence of deposits inhibiting the transmissionof light. By excluding wavelengths below 200 millimicrons and preferablybelow 280 millimicrons we significantly prolong onstream time beforedeposition interferes with light transmission and in turn with thereaction. We have found it beneficial to contemporaneously provide anintermittent or continuous flow of sulfuric or phosphoric acid over thereactor wall, particularly the light transmitting wall. Such flows havenot only materially assisted in inhibiting by-product deposition on thereactor wall but have substantially influenced the course of thereaction. However, not all concentrations of sulfuric or phosphoric acidhave been found to be beneficial when n-paraffins of the type describedherein are employed. While the art has suggested, for example, that anysulfuric acid concentration over 4 percent, that is, dilute,concentrated or fuming sulfuric acid may be employed, we have found thatonly a concentrated sulfuric or phosphoric acid and particularly acidsof from 85 to 98 percent, preferably 95 to 98 percent, are permissiblein the instant process. Employing dilute acids, i.e., 4to percentsulfuric acid, has prevented the photolysis reaction from occurring to asignificant extent and in some instances no reaction at all took place.Fuming sulfuric acid on the other hand has suppressed oxime formationwith resulting ketone and amide formation. Operable ranges stated above,which we term concentrated acids, surprisingly provide not onlyprolonged reactions free of optically interfering deposits but provideisolatable oximes. Further, when the concentrated acid flow is utilizedin combination with sodium arc lamp, a higher conversion in terms ofweight of product per kilowatthour is realized along with selectivitysuch that approximately 95 percent of the ultimate converted materialconsists of oximes, the remainder being predominantly ketones in therange of 3 to 5 percent.

In accordance with our invention the oxime is prepared by admixing anitrosating agent such as a nitrosyl halide, particularly nitrosylchloride and preferably with nitrogen and hydrogen chloride as diluentgases. The nitrosating agent is next contacted with a C to C n-paraffinat a temperature ranging from about 32 to about 110F., preferablybetween 50and F, in the presence of concentrated polybasic acid,preferably sulfuric acid, flowing along the reactor surface and actiniclight excluding wavelengths below 200 millimicrons. In operation, theconversion product comprises approximately 95 percent of the n-paraffinoxime salts of hydrochloric acid along with approximately 4 percent ofnitrosoalkyl chloride and approximately 0.2 percent of alkyl chloride.To achieve maximum light utilization the nparaffin is exposed to a lightsource contained in a glass water-cooled immersion well. Under theoperative conditions, oxime hydrochlorides precipitate to the bottom ofthe reaction vessel as an oily layer where they may be continuouslyremoved. The oximes are subsequently sprung by neutralizing the oximehydrochloride with aqueous ammonia, caustic soda or other base. Ingeneral, a typical apparatus consists of a reactor equipped with aquartz immersion well containing a mercury arc lamp fitted with a lightfiltering means intermittent the light source and the reaction zonewhereby wavelengths of less than 200 millimicrons are precluded frominfluencing the reaction. In place of mercury arc lamps any sourceproducing light in the wavelengths range of 200 to 760 millimicrons maybe employed including xenon arc, thallium arc, sodium arc and thetungsten incandescent lamp. By filtering out wavelengths below 200millimicrons, undesirable byproduct deposition on the light sourcedecreases while concommitantly increasing oxime yield. In our highlypreferred embodiment, sodium arc lamp is employ emitting wavelength offrom 380 to 760 millimicrons thereby permitting the photolytic reactionto take place in an apparatus as described above except that a lightfiltering means may be excluded.

Following the reaction, the reaction effluent is degased, preferablyunder vacuum, and any unreacted gaseous nitrosating agent is recoveredand recycled to the reaction. During the photolytic reaction,concentrated sulfuric acid to 98 percent) is continuously passed overthe quartz well reaction surface thereby removing and inhibiting thebuild-up by-product deposition. Inasmuch as the well cleaning sulfuricacid reacts with the oxime hydrochlorides, nitrosoalkyl chlorides andalkyl chlorides to produce sulfuric acid reaction products, theseproducts are subsequently released from their complex with sulfuric acidby first extracting the nitrosator effluent with a low boilinghydrocarbon such as cyclohexane, n-pentane, low petroleum ether orisoheptane, to remove unreacted nparaffins. In continuous operations theunreacted paraffins are recycled to the nitrosator and the paraffindenuded effluent is thereafter contacted with aqueous ammonia or gaseousammonia at a temperature ranging from about 32 to 140F., preferably fromabout 60 to ll0F., thereby separating the oxime and an aqueous ammoniumsulphate.

Approximately three volumes of cyclohexane or other low boilinghydrocarbon of the type mentioned above are mixed with the salts duringneutralization to facilitate the separation of the oximes from theaqueous phase. Substantially all of the inorganic salts fromneutralization are contained in the aqueous phase and additional waterwashing may be employed to remove the remainder of the inorganic salts.The cyclohexane phase from the neutralization reaction contains theoximes along with minor amounts of byproducts. The oximes may berecovered by blotter filtration and evaporation of the hydrocarbon underreduced pressure. Where desired the hydrocarbon may be condensed andrecycled for reintroduction to the extraction or neutralization stages.

Oximes produced in this manner from C to C nparaffins are valuable asengine oil additives, anti-icing agents, fuels, rocket propellents,fungicides, herbicides, and insecticides and have application in suchareas as pharmaceuticals, ore flotation, plastics and detergents.Moreover, the oximes may be hydrogenated to amines or converted toamides by Beckmann rearrangement as well as various other derivatives asby reaction with ethylene oxide to ethoxylates and with ethylene imineto ethaminates. Further, the oximes may be hydrolyzed to yield ketoneswhich are in turn hydrogenated to yield secondary alcohols.

In order to more fully illustrate the nature of our invention and mannerof practicing the same the following examples are presented.

EXAMPLE I The apparatus employed to photonitrosate C and highern-paraffins consisted of a l2-liter flask equipped with a quartzimmersion well containing a 550-watt high pressure mercury arc lamp. Theimmersion well was water jacketed to provide cooling to the lamp. Aglass tubing containing a terminal fritted glass gas dispersion tip wasused to deliver reactant gases to the bottom of the immersion well.Product and acid layer removal was accomplished by pumping off from thebottom of the reactor. Cooling of the normal paraffin phase wasaccomplished by circulation through a laboratory condenser connected toa chilled water circulation pump. Unreacted vent gases were lead to acaustic scrubber. A glass sparging ring located near the top of theimmersion well was used to deliver a film of acid to the immersion wellsurface for cleaning purposes. Charging funnels were used to supplynormal paraffins and fresh acid as needed. The sulfuric acid solution tobe used for cleaning the immersion well surface was added to thereaction flask to a level just below the fritted glass dispersion tipand normal paraffins were then added to the vessel until the levelreached the top of the mercury arc lamp. Cooling water to the immersionwell jacket was started as well as circulation of the normal paraffinthrough its cooling loop after which the reaction vessel was wrappedwith aluminum foil to provide an internal light reflecting surface. Whenthe paraffins reached the desired operating temperature the mercury arclamp was turned on and allowed to reach full operating intensity beforeintroducing the nitrosating gas mixture. This mixture consisted ofnitrosyl chloride, hydrogen chloride, and nitrogen in meteredproportions. Circulation of the bottom acid layer through the glasssparging ring was then started and adjusted so to provide an even washfilm on the immersion well. The reaction was terminated by turning offthe mercury arc lamp and gases and allowing the oxime salts toprecipitate completely. Examples utilizing filtered light employed aPyrex 7740 glass tube of two millimeters thickness. Approximately 60milliliters of 98 percent sulfuric acid per hour were sparged onto theimmersion well surface at 20 minute intervals for periods of 3 to 5seconds. This was found sufficient to maintain an optically cleansurface at all times. Sulfuric acid and oximes salts were removed fromthe reactor bottom and additional normal paraffins were added to replacethose used. By this means an efficient continuous reaction was afforded.Upon leaving the reactor the mixture of oxime salts and sulfuric acidwas degassed by agitating under vacuum. During this operation the oximehydrochlorides were converted to oxime sulfates and the liberated HClwas removed along with previously dissolved HCl and NOCl. Sufficientsulfuric acid was present on a 1:1 mole ratio to free the bound HCl soas to recover and recycle the HCl back to the reactor. Small amounts ofnormal paraffins, approximately 10 percent, entrained in theprecipitating oxime salts was removed by extracting the degassed saltswith cyclohexane and the nparaffin was recovered for recycle byevaporation of the low boiling hydrocarbon solvent. The n-paraffindenuded extracted oxime salt was thereafter neutralized with aqueousammonia. Approximately three volumes of cyclohexane was mixed with thesalts during neutralization to facilitate separation of the oximes fromthe aqueous phase. The aqueous phase contained the inorganic salts fromneutralization, ammonium sulfates, traces of ammonium chloride andadditional water washing removed the remainder of the inorganic matter.

In those examples employing a sodium arc lamp the equipment andprocedure was the same except that a lO-gallon reactor was employed,cooling was accomplished by a cooling coil within the photoreactor and60 ml sparging once each hour was undertaken employing concentratedsulfuric acid immersion well wash.

In a series of runs, the relationship between the nitrosating agentpartial pressure and oxime productivity employing HCl and nitrogen asdiluents was made at constant NOCl charge rates and various partialpressures. At an NOCl charge rate of 0.010 mole per minute and byvarying the partial pressure of NOCl from 100 to 600 mm Hg, maximumoxime formation occurred between 200 to 300 mm Hg partial pressure withoperative limits of from to 450 mm Hg. At an NOCl charge rate of 0.020mole per minute, maximum oxime formation occurred between 300 to 400 mmHg partial pressure with operative limits of from 125 to 625 mm Hg. Atan NOCl charge rate of 0.025 mole per minute, the maximum oximeformation and operative limits were similar to those conducted at acharge rate of 0.020 mole minute.

Table I below summarizes the results obtained in the amount ofconcentrated sulfuric acid contained presence or absence of washingagent. The data below therein. were obtained using unfiltered mercuryarc radiation. In the first experiment, the unit was operated at 70F.

TABLE I.EFFECT OF IMMERSION WELL WASHING AGENT AND UNFILTERED RADIATIONExample A B (I D E F Romurks... Extensive tar 1|(]lUSIl,il)ll Extensivetur deposition; 1mm product 10% oxime. No re: .tion, No reaction.Irorluut ketones and product 10% oxime. amides.

From the Table it will be seen that it was not possible and nitrosylchloride was blown in along with hydrogen to operate longer than 2 hourswithout an immersion chloride at the rate of 0.025 mole per minute forabout well washing agent. Further, dilute sulfuric acid or fum- 24hours. A pale yellow oxime oil was collected at the ing sulfuric acidwashing agents either produced no rate of 480 grams per kilowatt hour.Increasing the reaction or reactions culminating in products consist-NOCl rate to 0.031 mole per minute yielded an oxime ing of ketones andamides. Where concentrated suloil at the rate of 547 g/kwh. A furtherincrease in the furic acid was employed as the washing agent, oxime NOCIrate to 0.038 mole per minute yield an oxime oil products wererecovered. Table II summarizes the efat the rate of580 g/kwh. fect offiltered light on product formation. The 400 watt sodium arc lamp wasthen removed and 'FKBLE II.EFFECT OF FILTERED LIGHT ON PRODUCT FORMATIONExample G H I ,1

Washing agent 98% H2504 7 77 H 98% H2SO4 08% H2804 None. Filter None...vyrcx glass Pyrex glass Pyrex glass. Average NOCl charge rate (m0l./min.)0.020 0.010 0.020 0.020. Average crude product rate (g./min.) 1.08 1.01.47 Selectivity .1 gi- ;}94.5% oxime... 03.5% oxime 90% oxime, tardeposition.

Rate declined as tar deposition increased.

From the examples above it can be seen that both replaced by a 550 wattmercury arc lamp. The unit product formation rate and selectivity wereaffected operation was identical to that described with the sodiwhenlight of preferred wavelengths, excluding um arc lamp except that theNOCl rate was 0.036 mole wavelengths below 280 millimicrons wasintroduced per minute and wavelengths less than 280 millimicrons intothe reaction zone. Referring to Table II unfiltered were filtered by aPyrex 7740 glass immersion well. A li h lt d i a crude d t formation t fdark crude oxime oil was collected at the rate of 268 about 1.0 gram perminute as can be seen from Examg/ ple G. An equal level of productivitywas achieved at The aforementioned experiments clearly demon half theNOCl charge rate with filtered radiation, see Strate the Superiority andeffieiency of the Sodium are Example Further the Same NOC] charge rateslamp over mercury arc lamps for the photonitrosation of n-paraffins inachieving higher conversion rates over twice the productivity level perunit of electrical input. In operation, the sodium arc lamp alsoobviates the necessity of filtering solutions and devices. The sodiumarc lamp converts its electrical input energy directly into the visiblelight region in a highly efficient manner which excludes shorterwavelengths deleterious to photonitrosation reactions. This is realizedthrough imresulted in a percent oxime productivity increase as inExample I. The data in Table II also demonstrate that a selected rangeof radiation is necessary to achieve high reaction selectivity tooximes. Comparing Examples G, I, and J ketones were produced as a majorproduct in G whereas high oxime selectivity resulted, when filteredradiation was applied in examples I and J.

EXAMPLE 11 proved oxime quality as a result of reduced byproducts Thephotonitrosation apparatus equipped with a 400 50 zf fgh Lucalox Sodlump i f a R 1. A process for the manufacture of normal paraffin gisteredtrademark), having light emissions ranging oximes which comprises: from380 to 760 l'IllllIITllCI'ODS, where at least 50 percent aphotochemically reacting a normal paraffin having of the lamp emissionwavelengths are from about 550 from 10 to 13 carbon atoms with a gaseousto l ig a chargedfpmh w f of nitrosating agent selected from the groupconsista mlxture to 13 t e amp ing of nitrosyl halides, nitrosylsulfuric acid, operatmg m the absence of 3 filtenng device a nitrogenoxide and chlorine, nitrogen peroxide and nitrosating gas mixture ofnitrosyl chloride and chlorine each alone and in admixture with hydrogenchloride wasblown into the reaction media hydrogen chloride, where Saidnitrosating agent and ad usted to maintain the NOCl partial pressure atpartial pressure ranges from about to 625 mm 350 mm Hg and a totalpressure of one atmosphere. Hg under the influence of a Sodium arc p Thecrude oxime oil which collected at the bottom of providing essentially alight emission at a the reactor, along with the concentrated sulfuricacid wavelength from about 380 millimicrons and up to used for theemission well wash, was drawn off as about 760 millimicrons formed.Degassing was undertaken under vacuum with 5 separating the reactednormal paraffin and the strong agitation. The amount of oxime formedover a reaction products of) given Period of time was determined byweighing the c. neutralizing said separated reaction products ofdegassed liquid effluent and subtracting the known (bhand d. separatingand recovering normal paraffin oximes. 2. A process according to claim 1wherein the principal emission of said lamp is from about 550 to 650millimicrons.

3. A process according to claim 1 wherein said nitrosating agent isnitrosyl chloride.

4. A process according to claim 1 wherein said reaction is conducted ata temperature of from 32 to 1 10F.

5. A process according to claim 1 wherein said paraffin is a mixture ofC to C n-paraffins.

6. A process according to claim 1 wherein said UNKTED STATES PATENTOFFICE CERTIIFMATE er CORRECTWN nt No- 3,717-,561 Dated February 20,1973 Inventor(s) ORVILLE W. RIGDON, ROBERT S. EDWARDS, EDWARD H. HOLSTIt is certified that error appears in the above-identified patent andthat said Letters Patent are hereby corrected as shown below:

Col. 6 line 1 "20" should read 3o Signed end sealed this 27th day ofNovember 1973.

( L) Attest:

EDWARD NLFLETCHERJR. RENE D. TEGTJMEYER Attesting Officer ActingCommlsslonel" of Patents @933 UNRTED STATES PATENT ewnm CERTHHQA'EE GEfiUR-REQUEWN Patent No. 3 7 7- 5 7 Dated y 973 i fl ORVILLE W, RIGDOELROBERT SQ EDWARDS, EDWARD H. HOLST It is certified that error appears inthe above-identified patent and that said Letters Patent are herebycorrected as shown below:

Col. 6 line 14 "20" should read. 3O

Signed and sealed this 27th day of November 1973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. RENE D. TEGTMEYER Attesting Office-r ActingCommissloner of Patents

1. A process for the manufacture of normal paraffin oximes whichcomprises: a. photochemically reacting a normal paraffin having from 10to 13 carbon atoms with a gaseous nitrosating agent selected from thegroup consisting of nitrosyl halides, nitrosyl sulfuric acid, nitrogenoxide and chlorine, nitrogen peroxide and chlorine each alone and inadmixture with hydrogen chloride, where said nitrosating agent partialpressure ranges from about 125 to 625 mm Hg under the influence of asodium arc lamp providing essentially all light emission at a wavelengthfrom about 380 millimicrons and up to about 760 millimicrons, b.separating the reacted normal paraffin and the reaction products of (a),c. neutralizing said separated reaction products of (b), and d.separating and recovering normal paraffin oximes.
 2. A process accordingto claim 1 wherein the principal emission of said lamp is from about 550to 650 millimicrons.
 3. A process according to claim 1 wherein saidnitrosating agent is nitrosyl chloride.
 4. A process according to claim1 wherein said reaction is conducted at a temperature of from 32* to110* F.
 5. A process according to claim 1 wherein said paraffin is amixture of C10 to C13 n-paraffins.
 6. A process according to claim 1wherein said nitrosating agent partial pressure is from about 200 to 400mm Hg.
 7. A process according to claim 1 wherein a concentratedpolybasic acid at least intermittently flows over the reaction surfaceof said reaction vessel.
 8. A process according to claim 7 wherein saidpolybasic acid is sulfuric acid.
 9. A process according to claim 8wherein said acid is from 85 to 98 percent sulfuric acid.